Description (adapted from the application): The objective of the Physiology Core is to be a resource for DERC members to facilitate diabetes related research dealing with biological outcomes in normal and diabetic rodents (rats and mice) as well as in genetically engineered rodents generated in the Transgenic and Animal Genetics and Breeding Cores. These activities may require any or all of the following: (a) placement of catheters or probes for infusion and sampling (b) islet transplants, c) help in the performance of glucose clamps or tolerance tests, and (d) measurements of hormones or cytokines. The Physiology Core provides the centralized facilities, services and expertise to efficiently accomplish these tasks. It is divided into two Sub-cores, that is Animal Surgery and Hormone Assay. Dr. Sherwin, who is experienced in all of the methodologies offered by the Core, will serve as the Director of this Core and provide the administrative interface between the two Sub-cores and the DERC membership. The Physiology Core represents an expansion of the RIA Sub-core which was originally a component of the Clinical Metabolism Core. Its reconfiguration as a separate Core is the result of a series of steps that began with the polling of the membership as well as follow-up discussions with individual members. A plan was then presented to the Executive Committee and discussed at length during a visit of the external Advisory Board in May, 1996. The Core is designed to provide DERC investigators with access to sophisticated experimental methods for the analysis of glucose metabolism and hormone action or secretion, islet transplant surgery as well as assays for glucoregulatory hormones and cytokines. Although there are several DERC members whose laboratories are internationally-recognized for their ability to conduct complicated experiments in rodents, the access of most DERC investigators to such facilities is limited. The need for a centralized facility capable of performing such experiments has increased in recent years, as the numbers of genetically engineered rodents has increased. Moreover, we anticipate that our new program for the generation of transgenic rats will increase the need for access to such resources in the future. Thus, the expertise is available locally, and the establishment of the Physiology Core will now make it available to DERC investigators. This will allow them to more effectively utilize the animals generated in the Molecular, Transgenic and Animal Genetics Cores.